1. Field of the Invention
The invention relates to a recording and/or reproducing device for the recording and/or reproduction of information on a tape-shaped data carrier, this data carrier extending in a direction of tape travel and being capable of being moved forward in the direction of tape travel. The recording and/or reproducing device has a magnetic head for scanning the data carrier and at least one tape guide for guiding the data carrier past the magnetic head, wherein the tape guide has a curved guide wall and two guide flanges projecting beyond the guide wall, the guide flanges lying at a distance from one another in a direction extending perpendicularly to the direction of tape travel and adjoining the guide wall, each guide flange merging into the guide wall in a transitional area, wherein the sections of the tape guide that are located in the two transitional areas are able to exert, on the delimiting edges of the data carrier, a force that, in the event of an incorrect movement of the data carrier occurring perpendicularly to the direction of tape travel, counteracts this incorrect movement.
The invention further relates to a tape guide for a recording and/or reproducing device, this tape guide having a guide wall extending in a curve and two guide flanges projecting beyond the guide wall.
2. Description of the Related Art
A recording and/or reproducing device as defined in the first paragraph above having two tape guides of the kind defined in the second paragraph above, is disclosed in International Patent Application No. WO 01/61693 A1, corresponding to U.S. Pat. No. 6,550,658, which means that such a recording and/or reproducing device and such tape guides can be regarded as known.
As has already been explained in the patent cited above, it is possible, as the data carrier, in tape form that is formed by a magnetic tape, moves forward, for incorrect movements to occur in directions extending perpendicularly to the direction of tape travel, in which case the sections of the tape guide that are located in the two transitional areas between the guide wall and the two guide flanges then exert on the delimiting edges of the data carrier, a force that counteracts the incorrect movement described. In the case of the tape guides known from the above-mentioned patent, damping projections are provided in the area of the guide wall of the two tape guide rollers for the purpose of damping such incorrect movements.
Experiments and long-term tests have shown that, as a result of such incorrect movements and the effects that they cause the tape guides and the edges of the record-carrying tape to have on one another, there is both an unacceptably high degree of wear on the tape guides in the sections of the tape guides located in the two transitional areas between the guide wall and the two guide flanges, and also an unacceptably large amount of abrasion in the area of the two edges of the record-carrying tape, this abrasion tending to accumulate in the area of the guide walls of the tape guides, which, in turn, has the consequence that the standard of guidance provided by the tape guides suffers, and that there may be disruptions to proper recording or reproduction by the magnetic head due to the accumulations of abrasion. It should also be mentioned here that no indication is given in the above-mentioned patent of the material of which the known tape guides are composed in the known recording and/or reproducing device. It is known, however, for such tape guides to be manufactured from aluminum, because tape guides of this kind can be manufactured economically but, at the same time, with high precision, and to give a high standard of guidance, and for such tape guides of aluminum to be coated with a layer of nickel. It is also known for such tape guides to be made of brass or steel.
In connection with the problems referred to above, it has already been proposed that the tape guides be provided with a coating, the coating having a surface hardness of at least 10 GPa, corresponding to a value of at least 3200 HV (Vickers hardness). What have been proposed as possible materials in this case are titanium-aluminum nitride, tungsten carbide, silicon nitride, chromium nitride, and DLC (diamond-like carbon). Experiments on tape guides having a coating of one of the foregoing materials have revealed that the hardness of these materials did indeed render it possible to prevent an unacceptably high level of unwanted wear on the tape guides in their sections located in the two transitional areas between the guide wall and the two guide flanges, but it was still not possible to achieve satisfactory recording and/or reproducing conditions and long working lives because, with the tape guides examined that had a coating of one of the aforementioned materials, there was an unacceptably high accumulation of material abraded from the tape in the area of the guide walls of the tape guides.